Kidney autotransplantation after nephrectomy and work bench surgery as an ultimate approach to nephron-sparing surgery

Background: Kidney autotransplantation (KAT) is the ultimate approach for nephron-sparing surgery. It is a rarely used method in renal tumor surgery today as minimal invasive and open techniques for nephron-sparing surgery improve constantly. In this publication, the complication rate and the long-term functional and oncological outcome at a single center are analyzed. Methods: A prospectively constructed database of patients with renal tumors who underwent renal surgery was retrospectively analyzed to identify patients with KAT and describe surgical and oncological outcomes and to obtain long-term follow-up. Data collection included detailed surgical technique, complications (Clavian-Dindo), and hospital stay, as well as functional and oncological outcome and long-term follow-up. Results: Between 1976 and 2013, 12 patients (median age 50.5 years) underwent KAT for highly complex renal masses: in five cases for complex renal cell carcinoma (RCC), five cases for complex upper urinary tract carcinoma (UTUC), one case for a renal metastasis, and one case for nephroblastoma. The nephrectomy or nephron-ureterectomy was performed open via a flank or transabdominal. The median surgical time was 360 min (range 270-490 min). Intraoperatively, six cases required blood transfusions (50%). Six patients (50%) developed significant postoperative complications (Clavian-Dindo > 2). In two patients, intermittent hemodialysis for delayed graft function (16.6%) was needed, and in six cases (50%), additional blood transfusions postoperatively were necessary. At discharge from hospital, all patients had functioning grafts. The median hospital stay was 29.5 days (range 18-35). At follow-up (median follow-up of 83.5 +/- 40.7 months), six patients had died (50%)-all with functioning grafts (free from hemodialysis). In five cases, recurrence of primary tumor or metastatic disease was recorded. In four cases, the recurrent carcinoma could be resected; in detail, UTUC in three cases and one partial nephrectomy of the autotransplanted kidney was performed. One patient suffered from bone and lung metastasis. Two patients died finally tumor-related. Five patients (41.6%) are presently alive, without evidence of tumor relapse. One patient developed terminal renal failure requiring hemodialysis 105 months after autotransplantation. One additional patient was lost to follow-up; after 69 months, this patient had a functioning kidney and no evidence of disease-recurrence at the last follow-up. A cumulative number of 1424 months without hemodialysis was gained for these 12 patients. In the literature to date, most KAT are performed in benign disease, with minor but frequent complication. Here, we report the largest series of KAT for malignant kidney tumors. The complication rates are similar, compared to the recently reported series for benign indications with an improved graft survival rate. Since KAT requires a complex and challenging surgical approach, it should be performed by experienced kidney transplant surgeons. Conclusion: In very complex cases involving renal tumors and multi-morbidity, patients should be counseled well before KAT is considered. At the same time, KAT should not be abandoned in these very rare cases, especially when a nephron-sparing approach is otherwise not feasible. KAT can maintain renal function and quality of life and extend expectancy of life.